Question

a solid metal cylinder of radius 14 cm and height 21 cm is melted down and recast into spheres of radius 3.5 CM. show the number of spheres that can be made is :
A) 48
B) 54
C) 63
D) 72

Answer 1

let no, of spheres be N

by given,volume of the cylinder=NxVolume of spere

radius of cylindr=14cm

height of cylinder=21cm

volume=πr²h  =22/7 x 21 x 14 x 14

                       =12936 cm³

radius of sphere=3.5cm

volume=4/3πr³  =4/3 x 22/7 x 3.5 x 3.5 x 3.5

                          =179.66cm³

N=12936/179.66

   =72

thus 72 spheres can be made

Answer 2

this is the answer for the given question